{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90372","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.808Z","datePublished":"2026-09-17T16:09:12.733Z","dateUpdated":"2026-09-18T17:54:54.603Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-18T17:54:54.603Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss\n\nIf a peer's VHT/HE MCS map has no supported spatial stream (all fields\n0x3), the loop exits with nss == 0 and the function returned (u8)-1 (255),\nwhich was then written into the firmware sta_rec_bf beamforming fields.\nClamp the result to 0."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - A nearby 802.11 peer supplies the malformed MCS map in the HE Capabilities MCS NSS field of an Association Request. hostapd's NL80211_CMD_NEW_STATION reaches ieee80211_add_station()→sta_link_apply_parameters(), which copies he_mcs_nss_supp; mt76_sta_state(AUTH→ASSOC) then calls mt7915_mcu_get_sta_nss() on that map. WiFi radio range is Adjacent.\nAC:L - The attacker sets every 2-bit NSS field in HE rx_mcs_80 or rx_mcs_160 to 0x3. mt7915_mcu_get_sta_nss() then leaves its nss=8..1 loop with nss==0 and returns (u8)-1 (255) on every association. mac80211 does not reject an all-0x3 HE MCS map (unlike the 0xFFFF VHT check in ieee80211_vht_cap_ie_to_sta_vht_cap()). No race is involved.\nPR:N - mt7915_mac_sta_event(MT76_STA_EVENT_ASSOC) runs from sta_info_move_state(IEEE80211_STA_ASSOC) when hostapd's NL80211_CMD_NEW_STATION sets ASSOCIATED, before AUTHORIZED (the WPA 4-way handshake). 802.11 Open System authentication does not require a PSK or SAE credential on this path.\nUI:N - The attacker transmits the Association Request. ieee80211_add_station() and mt7915_mcu_add_sta() run in the AP kernel with no operator action on the victim device.\nS:U - The underflowed NSS is stored in the kernel sta_rec_bf TLV and sent to the on-device mt7915 MCU via MCU_EXT_CMD(STA_REC_UPDATE). Impact stays in the same kernel/device authority; this is not a VM, IOMMU, or sandbox escape.\nC:N - mt7915_mcu_get_sta_nss() only derives a u8 from the peer MCS map. That 255 is stored in sta_rec_bf.ncol_gt_bw80 or ibf_ncol; ncol used to index matrix[4][4] is min()'d with nrow, so there is no kernel OOB read and nothing is returned over the air.\nI:L - mt7915_mcu_sta_bfer_he() writes the underflowed nss_mcs (255) directly to sta_rec_bf.ncol_gt_bw80 on 160 MHz, and the implicit-VHT path writes it to ibf_ncol, then mt7915_mcu_add_sta() sends that TLV to firmware. That is a limited corruption of the chip beamforming profile, not an arbitrary kernel write.\nA:H - ncol_gt_bw80 and ibf_ncol are NSS counts the mt7915 MCU uses as beamforming dimensions. 255 is far outside the 0–3 range implied by the driver's matrix[4][4], so the firmware can hang or crash and take the radio down, and the peer can retrigger it on every association."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/mt7915/mcu.c"],"versions":[{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"2801477c36a19be4f549fe60e54995f03b0ea7b9","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"38f4d6323bcd65e41a691432eddabd2b03acdeee","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"25f753f7f620955a8a51e63e445d8b9076c51396","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"e63c6291ecddf94769ab91f9d8cdb6ca939f7fc6","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"85bd46ab7674b6d357f9a14791352c65fb09eee9","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"6ce78d04c7ea4b66838941b5a4232dd1ee0e2cc7","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"ecfd1a07e78c31d81322fb2d81dc468081cc3004","status":"affected","versionType":"git"},{"version":"89029a85482cbcf68026a89fc974e8f6898d6b37","lessThan":"4a2f4be532e3ea4e2b536e411793a05aaa51af25","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/mt7915/mcu.c"],"versions":[{"version":"5.8","status":"affected"},{"version":"0","lessThan":"5.8","status":"unaffected","versionType":"semver"},{"version":"5.10.270","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.221","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.188","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.110","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.52","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.6","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/2801477c36a19be4f549fe60e54995f03b0ea7b9"},{"url":"https://git.kernel.org/stable/c/38f4d6323bcd65e41a691432eddabd2b03acdeee"},{"url":"https://git.kernel.org/stable/c/25f753f7f620955a8a51e63e445d8b9076c51396"},{"url":"https://git.kernel.org/stable/c/e63c6291ecddf94769ab91f9d8cdb6ca939f7fc6"},{"url":"https://git.kernel.org/stable/c/85bd46ab7674b6d357f9a14791352c65fb09eee9"},{"url":"https://git.kernel.org/stable/c/6ce78d04c7ea4b66838941b5a4232dd1ee0e2cc7"},{"url":"https://git.kernel.org/stable/c/ecfd1a07e78c31d81322fb2d81dc468081cc3004"},{"url":"https://git.kernel.org/stable/c/4a2f4be532e3ea4e2b536e411793a05aaa51af25"}],"title":"wifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss","x_generator":{"engine":"bippy-1.2.0"}}}}